LTE (telecommunication) - Long Term Evolution
LTE is a standard for wireless communication of high-speed data for mobile phones and data terminals. The standard is developed by the 3GPP ( http://www.3gpp.org/LTE ).
LTE (Long Term Evolution) or the E-UTRAN (Evolved Universal Terrestrial Access Network), introduced in 3GPP R8, is the access part of the Evolved Packet System (EPS). The main requirements for the new access network are high spectral efficiency, high peak data rates, short round trip time as well as flexibility in frequency and bandwidth.
The LTE access network is simply a network of base stations, evolved NodeB (eNB), generating a flat architecture (figure 2). There is no centralized intelligent controller, and the eNBs are normally inter-connected viathe X2-interface and towards the core network by the S1-interface (figure 2). The reason for distributing the intelligence amongst the base-stations in LTE is to speed up the connection set-up and reduce the time required for a handover. For an end-user the connection set-up time for a real time data session is in many cases crucial, especially in on-line gaming. The time for a handover is essential for real-time services where end-users tend to end calls if the handover takes too long.
To understand the PS(protocol stack) of LTE which tells about data & signaling messages flow between different entities of LTE network interface. For more details about each layers one can refer below 3GPP specs. LTE PS is divided mainly into two categories NAS and AS Layers.
- NAS(Non-access stratum) Layer
- ESM & EMM. Refer 24.301 3gpp Spec and 23.401 3gpp Spec for EPC
- AS(Access Stratum) Layer
